US Patent 9,504,644: Scope, Claims, Expiration, and Varenicline Nasal-Spray Patent Landscape

US Patent 9,504,644 protects a method of increasing tear production by administering low-dose varenicline into the nasal cavity. The patent is method-of-use focused rather than a broad composition patent. Its central limitation is a locally administered, non-systemically bioavailable varenicline dose of 5 to 50 micrograms that activates peripheral nicotinic acetylcholine receptors without reaching the brain at pharmacologically relevant concentrations.

The patent is directly relevant to Tyrvaya, Oyster Point Pharma's varenicline nasal spray, which the FDA approved in 2021 for the treatment of signs and symptoms of dry eye disease. The patent's principal commercial value comes from the combination of four limitations: nasal administration, tear stimulation, low-dose varenicline, and avoidance of meaningful systemic or psychoactive exposure.[1][2]

What does US Patent 9,504,644 protect?

US 9,504,644 protects a therapeutic method, not every nasal formulation containing varenicline.

The independent claim requires all of the following:

Claim element	Required limitation
Therapeutic objective	Increasing tear production
Route	Local administration into the nasal cavity
Active ingredient class	Nicotinic acetylcholine receptor agonist
Specific agonist	Varenicline
Dose	5 to 50 micrograms per dose
Bioavailability	Non-systemically bioavailable dose
Receptor profile	Selective binding to peripheral nicotinic acetylcholine receptors
CNS limitation	No pharmacologically relevant blood-brain-barrier penetration

A product or treatment method that omits one of these limitations may fall outside claim 1, subject to the doctrine of equivalents and the construction adopted by a court.

The patent does not claim varenicline in every dosage form, every route of administration, or every indication. Oral varenicline for smoking cessation, for example, is materially different because it is systemically absorbed and is used for a different therapeutic purpose.

How broad is claim 1 of US 9,504,644?

Claim 1 is narrower than a generic claim to nasal nicotinic agonists because it expressly identifies varenicline and limits the administered dose to 5 to 50 micrograms.

Its breadth comes from the functional language surrounding the dose and pharmacology. The claim requires that the dose be:

Non-systemically bioavailable;
Selective for peripheral nicotinic acetylcholine receptors;
Non-psychoactive at the administered amount; and
Unable to cross the blood-brain barrier in a pharmacologically relevant concentration.

These limitations create potential infringement questions involving pharmacokinetic and pharmacodynamic evidence. A patent holder would likely need to establish the actual dose, route, exposure profile, receptor activity, and therapeutic effect of an accused product.

The term "increasing tear production" also matters. A nasal product that contains varenicline but is marketed exclusively for another indication may not satisfy the method claim unless the evidence shows use for increasing tear production. Induced infringement may arise if labeling, promotional materials, prescribing instructions, or clinical use direct the claimed method.

What do claims 2 through 15 add?

The dependent claims narrow the method through receptor subtype, safety, dosing frequency, formulation, delivery device, and neural mechanism.

Claims	Subject matter	Commercial significance
2	Alpha3beta4, alpha4beta2, or alpha7 receptor subtypes	Narrows receptor selectivity
3	No undesired psychoactive side effects	Supports low-CNS-exposure positioning
4	No undesired systemic side effects	Adds a tolerability limitation
5	Co-administration of agents that reduce receptor desensitization	Covers pharmacologic enhancement
6	PKC, PKA, or calcineurin-related agents	Defines the desensitization-control mechanisms
7	Cyclosporine, pimecrolimus, or tacrolimus	Specific calcineurin inhibitor combinations
8	At least once daily	Broad frequency limitation
9	At least twice daily	Covers the commercial Tyrvaya regimen
10	At least once weekly	Captures intermittent use
11	Liquid, suspension, aerosol, gel, ointment, dry powder, cream, paste, lotion, or balm	Covers multiple dosage forms
12	Syringe, dropper, nebulizer, atomization pump, inhaler, powder device, vaporizer, patch, pipette, or liquid jet	Covers delivery hardware
13	Trigeminal nerve activation	Adds a proposed neural mechanism
14	Anterior ethmoidal nerve activation	Further narrows the neural pathway
15	Nasolacrimal reflex activation	Claims a specific reflex mechanism

Claims 8 and 9 are commercially important because Tyrvaya is administered as one spray in each nostril twice daily. Claims 11 and 12 reach beyond the approved product by covering noncommercial formulations and devices.

What formulation and device technology does the patent cover?

Claims 11 and 12 cover the delivery format and device as claim limitations, but they do not independently claim a composition.

The formulation claim reaches:

Aqueous liquids;
Suspensions;
Aerosols;
Gels;
Ointments;
Dry powders;
Creams;
Pastes;
Lotions; and
Balms.

The device claim reaches a broad set of administration systems, including atomization pumps, nebulizers, inhalers, powder spray devices, and liquid jets.

This language gives the patent potential relevance to alternative nasal delivery platforms. A generic manufacturer using a metered nasal spray could face infringement risk under claim 1 or claim 9 without relying on claims 11 or 12. The formulation and device claims become more important where an accused product uses a nonstandard delivery system or where the prosecution history limits the interpretation of the independent claim.

The patent does not, based on the supplied claims, require a particular preservative, buffer, tonicity agent, viscosity modifier, container, pump geometry, particle-size distribution, or excipient system. Those features would generally require separate composition or device claims.

Does US 9,504,644 cover Tyrvaya?

Yes. Tyrvaya is a direct commercial embodiment of the claimed therapeutic concept.

The FDA-approved product contains varenicline tartrate equivalent to 0.03 mg varenicline per nasal spray. The label directs administration of one spray in each nostril twice daily, approximately 12 hours apart.[1] This corresponds to the patent's claimed low-dose nasal administration and twice-daily frequency.

The approved indication is treatment of the signs and symptoms of dry eye disease. The product's mechanism is associated with stimulation of the trigeminal parasympathetic pathway and increased basal tear production.[1][2]

Tyrvaya and claim mapping

Tyrvaya characteristic	Relevance to US 9,504,644
Varenicline nasal spray	Matches the active-agent limitation
0.03 mg per spray	Within the 5 to 50 microgram range per spray
Local nasal administration	Matches claim 1
Twice-daily dosing	Matches claim 9
Dry-eye indication	Consistent with increasing tear production
Nasal spray pump	Potentially within claim 12
Peripheral trigeminal pathway activation	Consistent with claims 13 to 15

The phrase "per dose" requires careful interpretation because the approved product delivers 30 micrograms per spray and one spray into each nostril per administration. A litigation analysis would need to determine whether the claimed dose is measured per actuation, per nostril, or per bilateral administration. The commercial product remains closely aligned with the claimed numerical range under the ordinary per-spray interpretation.

When does US Patent 9,504,644 expire?

US Patent 9,504,644 issued on November 29, 2016. Its publicly reported patent term is associated with a May 29, 2029 expiration date, subject to any applicable patent-term adjustment or other statutory modification.[3]

The practical exclusivity timeline is:

Date	Event
May 29, 2009	Earliest reported priority date for the patent family
2010	International or national-stage prosecution associated with the invention
November 29, 2016	US patent issued
October 15, 2021	FDA approved Tyrvaya
May 29, 2029	Reported patent expiration date
After expiration	Method claim no longer blocks ordinary practice of the claimed invention, subject to other unexpired rights

FDA approval does not itself extend the life of this patent. Patent-term extension under 35 U.S.C. § 156 and patent-term adjustment under 35 U.S.C. § 154 are separate mechanisms. The available public record should be checked against the official patent file and Orange Book entry before relying on a final launch date.

What is the Orange Book status of US 9,504,644?

US 9,504,644 has been associated with Tyrvaya's FDA exclusivity and patent listing record. The Orange Book identifies patents submitted by an NDA holder as covering the approved drug, its formulation, or an approved method of use.[4]

An Orange Book listing does not mean every claim in the patent necessarily covers every generic product. It means the NDA sponsor has submitted the patent for listing against the approved product. The listing can trigger a statutory certification obligation for an ANDA applicant.

For a generic nasal varenicline product, the relevant certification options generally include:

Paragraph III certification, accepting delayed approval until patent expiration;
Paragraph IV certification, asserting that the listed patent is invalid, unenforceable, or not infringed; or
A statement that the applicant is not seeking approval for the patented method, where permitted.

A Paragraph IV notice can result in patent litigation and a 30-month stay of FDA approval under the Hatch-Waxman framework if the NDA holder brings suit within the statutory period.[5]

Have generic manufacturers filed Paragraph IV challenges?

No established public record of a resolved Paragraph IV challenge to US 9,504,644 is identified in the materials provided. The patent remains the principal patent risk for a generic seeking approval of a low-dose varenicline nasal product that duplicates Tyrvaya's indication and dosing regimen.

A generic applicant could pursue several strategies:

File a Paragraph III certification and delay launch until patent expiry.
File a Paragraph IV certification and challenge validity, enforceability, or infringement.
Carve out the dry-eye indication or other patented method-of-use language.
Develop a noninfringing nasal product outside the claimed dose range.
Use a different active ingredient or a different therapeutic mechanism.

A section viii carve-out would be difficult if the generic product's labeling still directs administration for increasing tear production. The commercial value of a nasal varenicline product depends heavily on the dry-eye indication, which is the same field covered by the patent.

What validity issues could affect US 9,504,644?

The strongest potential validity issues would concern written description, enablement, obviousness, indefiniteness, and the relationship between the broad functional limitations and the specific varenicline embodiment.

Obviousness

A challenger could combine prior art relating to:

Nicotinic acetylcholine receptors in the nasal cavity;
Trigeminal or nasolacrimal reflexes;
Tear stimulation by nasal stimulation;
Varenicline pharmacology;
Local nasal drug delivery; and
Avoidance of central nervous system exposure.

The patent holder would likely rely on the claimed low dose, localized exposure, tear-production result, and absence of psychoactive effects as a combination that was not predictable from the individual references.

Enablement and written description

The claims cover multiple receptor subtypes, formulations, devices, dosing frequencies, and desensitization-control agents. A challenger could argue that the specification does not enable the full scope, particularly for combinations involving PKC modulators, PKA modulators, or calcineurin inhibitors.

Claim 1 is more defensible if the specification contains experimental data for low-dose nasal varenicline and tear production. The broader dependent claims may face greater scrutiny if the disclosure provides limited examples across the claimed formulations and mechanisms.

Indefiniteness

Potentially contestable terms include:

"Selectively binds";
"Peripheral nicotinic acetylcholine receptor";
"Non-systemically bioavailable";
"Pharmacologically relevant concentration";
"Undesired psychoactive side effects"; and
"Undesired systemic side effects."

These terms may be construed in light of the specification and technical knowledge. Their functional nature can increase litigation cost because infringement and validity may depend on expert testing rather than simple product-label comparison.

How strong is the patent estate for Tyrvaya?

US 9,504,644 is commercially meaningful but does not, standing alone, create a complete product monopoly over all dry-eye nasal therapies.

Strengths

It directly covers low-dose nasal varenicline for tear production.
The claim aligns closely with the approved Tyrvaya regimen.
The dose range is specific enough to distinguish ordinary oral varenicline treatment.
The claim includes pharmacologic and CNS-exposure limitations that match the product's local-acting profile.
Dependent claims cover twice-daily dosing, devices, formulations, and neural mechanisms.

Weaknesses

Claim 1 contains multiple functional limitations.
The dose interpretation could become important in an infringement dispute.
The patent does not appear from the supplied claims to protect every varenicline formulation or every nasal product.
Broad dependent claims may invite enablement and written-description challenges.
A competitor could pursue a different active ingredient or a materially different dose and administration strategy.

The patent is strongest against a product that reproduces the approved Tyrvaya profile: varenicline, nasal delivery, approximately 30 micrograms per spray, twice-daily administration, and dry-eye labeling.

What other patents and exclusivity rights affect Tyrvaya?

US 9,504,644 should be evaluated as one component of a broader product estate. The relevant categories are:

Protection category	Strategic role
Core method-of-use patents	Protect nasal varenicline for tear production
Formulation patents	Protect concentration, excipients, stability, or spray performance
Device patents	Protect metered-dose pumps and delivery geometry
Follow-on method patents	Protect dosing, patient populations, or treatment protocols
Regulatory exclusivity	Delays certain FDA approvals independent of patent validity
Trade secrets	Protect manufacturing processes, filling, testing, and device assembly
Trademark rights	Protect Tyrvaya branding but do not block generic substitution

Tyrvaya is a small-molecule product. Biosimilar law does not apply. A competing varenicline nasal spray would generally proceed through the ANDA pathway if it could establish pharmaceutical equivalence and bioequivalence, or through a 505(b)(2) application if it relied on a different formulation, device, dosage form, or clinical bridge.[6]

The main commercial barrier is therefore an ANDA patent challenge, not biosimilar litigation.

What generic launch scenarios exist?

Scenario 1: Delayed ANDA launch

A generic files with a Paragraph III certification and launches after expiration of the listed patent and any other blocking rights. This is the lowest-litigation pathway but delays market entry.

Scenario 2: Paragraph IV litigation

A generic asserts that the patent is invalid, unenforceable, or not infringed. The NDA holder may sue, triggering the statutory stay. The outcome would turn on claim construction, prior art, dose interpretation, and evidence concerning CNS exposure and peripheral receptor activity.

Scenario 3: Label carve-out

A generic seeks approval without the patented dry-eye method. This strategy has limited commercial value if the principal market is tear-production treatment.

Scenario 4: Noninfringing formulation or dose

A competitor could use another nicotinic agonist, a dose outside the claimed range, or a route that does not satisfy the nasal-local-administration limitation. This strategy would face clinical, regulatory, and commercial risks.

Scenario 5: 505(b)(2) competition

A sponsor could develop a modified nasal varenicline product or alternative delivery system and seek approval through a 505(b)(2) application. This would not eliminate patent risk. The sponsor would still need to address listed patents and any applicable method-of-use rights.

What manufacturing and geographic barriers remain?

The patent has US territorial scope. It does not directly block a product manufactured and sold entirely outside the United States, although US importation, commercial use, or sale can create infringement exposure.

Manufacturing risk extends beyond the claimed method. A competitor must reproduce:

A stable low-dose varenicline formulation;
Consistent metered spray delivery;
Nasal deposition at the intended site;
Acceptable preservative and excipient performance;
Container-closure integrity;
Device reliability across the labeled shelf life; and
Batch-to-batch dose uniformity.

These requirements can create practical barriers even where a competitor avoids literal infringement. Device qualification and nasal spray bioequivalence can be more complex than ordinary oral solid-dose development.

What litigation and settlement issues matter?

A dispute involving US 9,504,644 would likely center on four issues:

Whether the accused product administers varenicline within the claimed 5 to 50 microgram range.
Whether the dose is non-systemically bioavailable.
Whether the product is used or labeled for increasing tear production.
Whether the product satisfies the peripheral receptor and blood-brain-barrier limitations.

A settlement could take the form of:

A delayed generic entry date;
A license with royalty payments;
A product-specific carve-out;
A covenant not to sue;
A supply or authorized-generic arrangement; or
Restrictions on the generic's label and promotional activities.

No settlement terms can be inferred from the patent claims alone. Any analysis of a specific agreement must rely on the filed settlement, FTC review, court docket, or FDA correspondence.

Key Takeaways

US 9,504,644 is a method-of-use patent centered on low-dose nasal varenicline for increasing tear production.
Claim 1 requires nasal administration, varenicline, a 5 to 50 microgram dose, peripheral receptor selectivity, limited systemic exposure, and no pharmacologically relevant blood-brain-barrier penetration.
Tyrvaya closely matches the patent through its 30 microgram-per-spray dose, twice-daily nasal administration, and dry-eye indication.
Claims 8, 9, 11, and 12 are the most commercially relevant dependent claims for the approved product and standard nasal-spray competition.
The reported patent expiration date is May 29, 2029, subject to the official patent-term record.
Generic competition would likely proceed through an ANDA, with Paragraph III, Paragraph IV, or section viii strategies.
Biosimilar risk is not applicable because varenicline is a small molecule.
The patent is strongest against a direct Tyrvaya substitute and weaker against alternative agonists, materially different doses, and non-nasal therapies.
Formulation, device, manufacturing, and follow-on patents may materially extend the practical exclusivity period beyond this single patent.

FAQs

Does US 9,504,644 cover oral varenicline?

No. The claims require local administration into the nasal cavity. Oral varenicline for smoking cessation does not satisfy the claimed route or the claimed local, non-systemic exposure profile.

Can a generic use varenicline for dry eye before May 2029?

Only if it obtains approval and avoids or successfully challenges the applicable patent rights. A generic that duplicates the claimed nasal varenicline method would face substantial Paragraph IV litigation risk.

Does changing the nasal spray device avoid infringement?

Not necessarily. Claim 1 does not require a specific device. A different pump could still infringe if the product satisfies the active ingredient, dose, route, therapeutic purpose, and pharmacologic limitations.

Is a varenicline nasal spray at 60 micrograms automatically outside the patent?

It would be outside the literal 5 to 50 microgram range in claim 1, but infringement could still depend on dose measurement, claim construction, and the doctrine of equivalents. A different dose would also require independent regulatory and clinical support.

Does the patent protect increased tear production caused by any nasal nicotinic agonist?

Claim 1 is limited to varenicline. Other nicotinic agonists may fall within broader disclosure or related family claims, but they are not covered by the supplied text of claim 1 solely because they increase tear production.

References

U.S. Food and Drug Administration. (2021). Tyrvaya (varenicline solution) nasal spray prescribing information. FDA.
Oyster Point Pharma, Inc. (2021). Tyrvaya FDA approval announcement and product information. Oyster Point Pharma.
United States Patent and Trademark Office. (2016). U.S. Patent No. 9,504,644, nasal administration of nicotinic acetylcholine receptor agonists for treating dry eye. USPTO.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.
United States Code. 35 U.S.C. § 271(e); 21 U.S.C. § 355(j).
U.S. Food and Drug Administration. (2023). Applications covered by section 505(b)(2). FDA.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Oyster Point Pharma	TYRVAYA	varenicline tartrate	SPRAY;NASAL	213978-001	Oct 15, 2021		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial				TREATMENT OF THE SIGNS AND SYMPTOMS OF DRY EYE DISEASE (DED)	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2015336216	⤷ Start Trial
Australia	2020213351	⤷ Start Trial
Brazil	112017008097	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,504,644

Which drugs does patent 9,504,644 protect, and when does it expire?

Summary for Patent: 9,504,644